1. Field of the Invention
The present invention relates to a production method of an electroluminescence light emitting device and the like, and specifically, relates to a production method of a light emitting device in case of using a material containing a polymer for a light emitting material.
2. Description of the Related Art
An organic EL (electroluminescence) light emitting material is largely divided into a low molecular weight type material practically used at present and a polymer type material which is promising in future development. Among these, when the low molecular weight type material is used, the film forming of a light emitting layer is usually carried out by a vacuum deposition method. In this case, the light emitting layer can be patterned by a method of piling up on a substrate a shadow mask in which an opening corresponding to a pixel is formed and depositing the material, therefore a fixed form corresponding to the pixel, for example, a dot form light emitting layer can be formed. Further, a light emitting layer having a plural number of light emitting colors in accordance with a fixed arrangement can be formed by repeating the above-mentioned processes by every respective light emitting colors.
Thus, when a low molecular weight type organic EL light emitting material is used, the light emitting layer can be patterned in a fixed form by the above-mentioned method. However, when a polymer type organic EL light emitting material is used, a vacuum deposition method cannot be used as a method of forming the film of the light emitting layer because the polymer type organic EL light emitting material is not deposited by heating but decomposed. Although a solution coating method such as spin-coating or dip-coating or the like can be used when the film of the polymer type organic EL light emitting material is formed, there are problems that it is difficult to partially form a coating film and it is difficult to form the light emitting layer in a fixed form.
The object of the present invention is to provide a light emitting device capable of easily forming a fixed form light emitting layer irrespective of the kind of light emitting materials, and a production method thereof.
To solve the problem, the light emitting device of the present invention is characterized in that light emitting layers are formed by electrophotography, in a light emitting device in which the light emitting layers are composed of a material containing a polymer.
According to the invention, since the light emitting layers is formed by electrophotography, the light emitting layers can be formed in a fixed form irrespective of the kind of light emitting materials of the light emitting layers. Further, the number of processes for formation of the light emitting layers can be reduced in comparison with a vacuum deposition method and the like.
To solve the problem, the light emitting device of the present invention is characterized in that light emitting layers are formed by a thermal transfer or sublimation method, in a light emitting device in which the light emitting layers are composed of a material containing a polymer.
According to the invention, since the light emitting layers are formed by a thermal transfer or sublimation method, the light emitting layers can be formed in a fixed form irrespective of the kind of light emitting materials of the light emitting layers. Further, the number of processes for formation of the light emitting layers can be reduced in comparison with a vacuum deposition method and the like.
To solve the problem, the production method of a light emitting device of the present invention is characterized in that a process of forming light emitting layers by electrophotography is included, wherein the light emitting layers are composed of a material containing a polymer.
According to the invention, since the light emitting layers are formed by electrophotography, the light emitting layers can be formed in a fixed form irrespective of the kind of light emitting materials of the light emitting layers. Further, the number of processes for formation of the light emitting layers can be reduced in comparison with a vacuum deposition method and the like.
The production method may include a process of forming the light emitting layers on a transfer member by electrophotography and a process of transferring the light emitting layers which were formed on the transfer member on the substrate of the light emitting device.
In this case, since the light emitting layers are transferred through the transfer member, the light emitting layers for various kind of the substrates can be formed by selecting the transfer member in accordance with the kind of the substrates. For example, when a member having elasticity is used as the transfer member, it comes to be able to be corresponded with a hard substrate composed of glass or the like.
To solve the problem, the production method of the light emitting device of the present invention is characterized in that a process of forming light emitting layers by a thermal transfer or sublimation method is included, wherein the light emitting layers are composed of a material containing a polymer.
According to the invention, since the light emitting layers are formed by a thermal transfer or sublimation method, the light emitting layers can be formed in a fixed form irrespective of the kind of light emitting materials of the light emitting layers. Further, the number of processes for formation of the light emitting layers can be reduced in comparison with a vacuum deposition method and the like.
The production method may include a process of forming the light emitting layers on a transfer member by a thermal transfer or sublimation method and a process of transferring the light emitting layers which were formed on the transfer member on the substrate of the emitting device.
The light emitting layers may contain at least one or more of light emitting materials emitting light by impressing electric field. In this case, the light emitting layers may be formed by dispersing not only those which are polymers such as a poly(p-phenylene vinylene) derivative, a polythiophene derivative, or a fluorene derivative, as they are, but also a low molecular weight light emitting material, in a polymer binder.